Self-mooring of a ship to a one-point mooring buoy

ABSTRACT

A method and apparatus for self-mooring a ship to a one-point mooring buoy, the mooring cables and floating hoses of the onepoint mooring buoy being kept in a stretched condition by a hollow cone and drag offering resistance to the water current so that the ship can easily pick up the mooring cables and hoses by means of a grapple.

United States Paten t [1 1 Macdonald [111 3,747,136 1 Early 24, 1973SELF-MOORING OF A SHIP TO A ONE-POINT MOORING BUOY [75] Inventor: AdamMacdonald, Bettyhill, by

Thurso, Caithness, Scotland [73] Assignee: Shell Oil Company, New York,NY.

[22] Filed: Mar. 19, 1971 [21] Appl. No.: 125,976

[30] Foreign Application Priority Data Apr. 10, 1970 Great Britain17,158/70 [52] US. Cl 9/8 P, 114/230 [51] Int. Cl 1363b 35/00, B63b21/52 [58] Field of Search 9/8 P; 114/209, 235 R,

[56] References Cited UNITED STATES PATENTS 3,466,680 9/1969 ISchirtzinger 9/8 P 3,595,195 7/1971 Van Eek 9/8 P 3,354,479 11/1967lioppenol et a1. 9/8 P 2,721,530 10/1955 2,942,371 6/1966 2,537,3211/1951 3,619,832 11/1971 2,744,352 5/1956 Primary ExaminerDuane A. RogerAssistant Examiner-Gregory W. O'Connor Attorney-Theodore E. Biebcr andHarold L. Donklcr [57] ABSTRACT 41 Claims, 4 Drawing Figures "m m 4 2II. N J n E T N E TI- A pl A. Mac Donald INVENTOR SELF-MOORING OF A SHIPTO A ONE-POINT MOORING BUOY BACKGROUND OF THE INVENTION The inventionrelates to a method and apparatus for the self-mooring of a ship to aone-point mooring buoy for loading or unloading a fluid into or from aship.

One-point mooring buoys for loading or unloading a fluid into or from aship are widely known and are being used in increasing numbers. In usethe ship is fastened by its bow to the one-point mooring buoy by meansof a mooring cable in such a manner that the ship is capable of swingingaround the buoy with its bow pointing towards the buoy. The one-pointmooring buoy is provided with the mooring cable and with a hose floatingon the water, which hose is coupled to the ship after the latter hasmoored to the one-point mooring buoy, whereupon the loading or unloadingof the fluid via the hose and the one-point mooring buoy is commenced.For the purpose of mooring the ship to the one-point mooring buoy andfor connecting the floating hose to the ship, use is normally made of amanned mooring launch.

However, in locations where the sea is very rough during a large part ofthe year the mooring launch cannot be used to assist in mooring the shipand connecting the floating hose. In these circumstances, it would beadvantageous to have a method and an apparatus allowing the ship to moorto the buoy and to connect the floating hose to the ship without theassistance of a manned mooring launch.

BRIEF SUMMARY OF THE INVENTION To this end, the invention relates to amethod for the self-mooring of a ship to a one-point mooring buoy forloading or unloading of a fluid into or from a ship, wherein a rope issecured to the free ends of the buoys mooring cable and floating hoseand wherein means offering resistance to the water current are securedto the rope in such a manner that a loop is formed by the ropemaintaining the buoys mooring cable and floating hose permanently in astretched condition by forces acting on. the mooring cable and thefloating hose and created by the water current, subsequently picking upthe loop together with the mooring cable and the floating hose from onboard an arriving ship, connecting the mooring cable and the floatinghose to the ship and finally loading or unloading the fluid into or fromthe ship.

A system for use with the above method comprises, according to theinvention, a one-point mooring buoy,

provided with a mooring cable and a floating hose,

wherein a rope is secured to the free ends of the buoys mooring cableand floating hose and wherein means offering resistance to the watercurrent are secured to the rope in such a manner that a loop is formedby the rope and that the mooring cable and the floating hose aremaintained in a stretched condition.

BRIEF DESCRIPTIONOF THE DRAWING The invention will now be described withreference to the drawings which represent an embodiment of theinvention.

FIG. I is a top plan view of a mooring system according to theinvention.

FIG. 2 shows in detail a side view of a cone for use in the systemaccording to the invention.

FIG. 3 shows in detail a top plan view of a drag'for use in the systemaccording to the invention.

FIG. 4 shows a side view of the drag according to FIG. 3.

DESCRIPTION OF A PREFERRED EMBODIMENT In FIG. 1, a conventionalone-point mooring buoy l is shown schematically. This buoy l is floatingin the water 2 and is anchored in a conventional manner to the seabed(not shown). The buoy 1 is provided with a pair of floating hoses 3 and4 of conventional construction. Furthermore, the buoy l is provided witha pair of mooring cables 5 and 6, for example made of nylon. By means ofwires 7, 8 and 9 an end of a rope 10 is connected to the free ends ofthe floating hoses 3 and'4. The other end of the rope 10 is connected tothe free ends of the mooring cables 5 and 6 by means of wires 11 and 12.A suitable material for the rope 10 is, for example, polypropylene. Ahollow cone l3 and a drag 14 are secured to the rope 10, as shownschematically in FIG. 1, by means of nylon cable 15 respectively 16.

The hollow cone 13 is shown more in detail in FIG. 2. It is, forexample, made of a suitable textile material or plastic sheet material.The cone is open at both ends so that water is allowed to flow throughthe inside of the cone. The large end of the cone is provided withcables 18, secured to the periphery of the cone. The free ends of thecables are interconnected by means of a ring 19. Another ring 20 isconnected to ring 119 by means of a rope 21.

The drag 14 consists of a rigid plate 25 provided with a number of bars26. The free ends of the bars 26 are interconnected by means of a ring27. Another ring 28 is secured to ring 27.

The cone 13 is secured to the rope 10 by means of the nylon cable 15.One end of the nylon cable 15 is secured to the ring 20 and the otherend of the nylon cable 15 is secured to the rope 10.

The drag 14 is secured to the rope 10 by means of the nylon cable 16.One end of the nylon cable 16 is secured to the ring 28 and the otherend of the nylon cable 16 is secured to the rope 10.

The floating hoses 3 and 4 and the mooring cables 5 and 6 are connectedto the turntable of the one-point I mooring buoy 1, which isconventional. The cone 13 and the drag 14 are devices offeringresistance to the flow of the water. The effect of the friction of thetidal stream or current coupled with any wave action of the cone l3 andon the drag 14 will permanently keep the rope 10, the mooring cables 5and 6 and the hoses 3 and 4 in a stretched condition. As shown in FIG.1, the rope 10 is caused to form a loop.

OPERATION When a ship, for example a tanker, arrives at the mooring buoyl, a grapple is lowered from the ship and by means of this grapple, therope 10 is picked up by the ship. After recovering of the rope III thelatter is heaved in on the winch of the ship. In this manner the ship isheaved towards the one-point mooring buoy 1 until the mooring cables 5and 6 are securely attached to the bollards of the ship. On completionof the mooring operation by heaving in on the remaining part of the ropel0, access to the floating hoses 3 and 4 is ensured in order tofacilitate hose connection. The hoses 3 and 4 are then connected to theship, whereafter loading or unloading of fluid into or from the ship canstart and in this manner the ship has moored itself to the one-pointmooring buoy without assistance of a manned mooring launch.

The unmooring procedure of the ship is as follows.

After disconnecting the hoses 3 and 4 from the ship, one end of the rope10 is again connected to the ends of the hoses 3 and 4 and the other endof the rope 10 is again connected to the ends of the mooring cables 5and 6. Then the floating hoses 3 and 4 are lowered or slipped by meansof slip ropes into the sea and allowed to stream parallel to the ship.The mooring cables 5 and 6 are then released from the ships bollards andas the ship gathers sternway during unberthing, the rope 10 remainingonboard is payed out from about midship and the cone l3 and drag 14 arelaunched. Then the berth is left ready to receive the next self-mooringship.

It is to be understood that instead of using two floating hoses, it ispossible to use only one floating hose or more than two floating hoses.Also, instead of using two mooring cables, it is possible to use onlyone mooring cable or more than two mooring cables. Furthermore, insteadof using one cone and one drag, it is possible to use two or more conesand drags.

I claim as my invention:

1. An apparatus for self-mooring of a ship to a onepoint mooring buoyfor loading or unloading a fluid into or from a ship, comprising:

a one-point mooring buoy;

a mooring cable being connected to said mooring buoy;

a floating hose being connected to said mooring buoy;

a rope being connected at its freeends to said mooring cable andfloating hose;

a means offering resistance to the water current being connected to saidrope comprising first means for maintaining said mooring cable andfloating hose permanently in a stretched condition and second meansspaced from said first means for forming an open loop with said rope.

2. The apparatus of claim 1 wherein the means offering resistance to thewater current comprises:

a drag being connected to said rope; and

a hollow cone open on both ends being connected to said rope.

3. A method for self-mooring ofa ship to a one-point mooring buoy forloading or unloading a fluid into or from a ship which comprises:

connecting a rope at its free ends to the mooring cable and floatinghose on said buoy;

attaching to said rope a first means offering resistance to watercurrent;

attaching to said rope a second means offering resistance to said watercurrent spaced from said first means;

subjecting said first and second means to said water current;

spreading the mooring cable from said floating hoses to form a loop byforces acting on said first and second means;

picking up said loop from onboard a ship;

heaving in said rope by means onboard ship until said mooring cable issecurely attached to said ship; and

connecting said hose to said ship.

4. The method of claim 3 wherein the loop in said rope is picked up fromonboard ship by use of a grapple lowered from said ship.

1. An apparatus for self-mooring of a ship to a one-point mooring buoyfor loading or unloading a fluid into or from a ship, comprising: aone-point mooring buoy; a mooring cable being connected to said mooringbuoy; a floating hose being connected to said mooring buoy; a rope beingconnected at its free ends to said mooring cable and floating hose; ameans offering resistance to the water current being connected to saidrope comprising first means for maintaining said mooring cable andfloating hose permanently in a stretched condition and second meansspaced from said first means for forming an open loop with said rope. 2.The apparatus of claim 1 wherein the means offering resistance to thewater current comprises: a drag being connected to said rope; and ahollow cone open on both ends being connected to said rope.
 3. A methodfor self-mooring of a ship to a one-point mooring buoy for loading orunloading a fluid into or from a ship which comprises: connecting a ropeat its free ends to the mooring cable and floating hose on said buoy;attaching to said rope a first means offering resistance to watercurrent; attaching to said rope a second means offering resistance tosaid water current spaced from said first means; subjecting said firstand second means to said water current; spreading the mooring cable fromsaid floating hoses to form a loop by forces acting on said first andsecond means; picking up said loop from onboard a ship; heaving in saidrope by means onboard ship until said mooring cable is securely attachedto said ship; and connecting said hose to said ship.
 4. The method ofclaim 3 wherein the loop in said rope is picked up from onboard ship byuse of a grapple lowered from said ship.